multiplayer

[hollow ridge]

Now idea lol

[sinful tree]

Why are you even doing a multicast?

What is focused actor set to to begin with?

[hollow ridge]

I've a trace system and thats connected to the actor as child and If I look at something (lets say a platform in this example) I press E and want to get the parent from my actor. My actor at this situation is the collision sphere child from that platform.

and behind that interact functions is a simple move component to xyz

That "InteractionArea" would be the FocusedActor

[sinful tree]

Normally when interacting you do something like:
1 Player Side) Player Pressess Input > Does some tracing to find an actor > If finds a valid actor > Sends a Run On Server event passing along reference to the actor you want to interact with (Add an Actor Reference as an Input to the event).
2 Server Side) Run On Server Event > Validates player should be able to interact (player within range checks, not dead, etc.) > Calls Interaction Interface on the Actor
3 Server Side) Interaction Implementation on Actor > Does whatever is required for this actor to be interacted with, set any replicated values, trigger any other events or functions, destroy itself, call a multicast if required, or do whatever else you need it to do when it is interacted with

[hollow ridge]

Hmm, I guess I've to search then and try to figure that out. New topic for me x)
Thank you a lot! I'll try to refacture a lil bit and see how it goes

[half umbra]

@dark edge yes?

[oak pond]

does unreal have a weird thing with spawning actors in a for loop? I have a shotgun type weapon which uses a for loop to spawn multiple projectile actors, but in multiplayer, the for loop just spawns 2? Ive used a print to check it and its showing me the for loop is working fine but theyre just not spawning

actually, those are only on the server, and just 2 for each client. but this is on a multicast, and the for loop isnt replicated, just the event that spawns

[thorny citrus]

Hello, I'm curently trying to setup a dedicated server for lyrastartergame following these two tutoriasl https://www.youtube.com/watch?v=bw4zDuH3v54, https://www.youtube.com/watch?v=_7TQynJ_TrQI'm . I'm currently on 00:48 on this tutorial: https://www.youtube.com/watch?v=bw4zDuH3v54. However after I set my startup project to UE5 and clicked on the windows debugger, it starts building but its been building forever. I'm hitting my 10th hour without it finishing. This is the 2nd attempt this has happened. Does anyone have any ideas? I need help 😅 - or if anyone knows how to setup a dedicated server for lyra in general, It would be greatly appreciated if someone explained that to me.

[oak pond]

guess Ill wait until tomorrow

[sinful tree]

You're going about this all wrong. There should be no real reason for:
A) A client to tell the server to spawn weapons.
B) A client looping to tell the server repeatedly how many weapons should be spawned.
C) A client to tell the server what position to spawn them in.
D) Having each client spawn a copy of the weapon.

The server should be able to spawn weapons on its own without a client RPC, unless of course your client is "Dropping" a shotgun, but that still shouldn't be a direct thing that a client should be able to call.

The server should likely determine the rotation to spawn the shotguns rather than the client being able to arbitrarily tell the server the rotation.

If you do want your client to be able to tell the server to spawn a shotgun, that's fine, but you shouldn't be looping the RPC. Instead, put the loop on the server so the server can do it and if you want the client to be able to tell the server an amount, include an input on the RPC to include a desired number. It's probably not spawning all of them because you're overflowing the network, as you're looping 16 times, then running a multicast 16 times.

If your ShotGun is a replicated actor, you would only need to spawn it on the server, so you wouldn't require to even call a multicast to spawn them, just spawn them on the server, and they'll replicate as they are able to clients.

[oak pond]

its not... weapons

I just called it shotgun for convenience these are just projectiles

[sinful tree]

Oh sorry I see, it's the projectiles...

[oak pond]

yeah I didnt realise I made it look that way

[sinful tree]

Even still, not the right way... Client shoots > Server determines rotation > Server Spawns Projectiles

[oak pond]

thats one of the things I tried

yeah, just checked again and changing it to a server event makes no difference

[sinful tree]

At the very least, you wouldn't want to multicast the spawning of the projectiles, nor should you be sending an RPC in a loop to the server, one RPC to the server should suffice for triggering an activation.

[oak pond]

so if the rpc isnt in a loop how is it randomising each spawn rotation without being different on each client?

also it just wont let me spawn actors from the server

[sinful tree]

You do the loop to spawn on the server. You don't need to loop on the client to tell the server to shoot them individually
Are your projectiles marked as replicated?

[oak pond]

which part? it does replicate the two that fire completely fine

and with a different weapon type it was all fine

[sinful tree]

An actor being marked as replicated is not the same thing as sending RPCs.

A replicated actor means you can spawn it on the server and a copy will then appear on relevant clients.

What you are doing is telling each client to spawn their own actors which would not be considered replicated as they weren't spawned by the server itself.

[oak pond]

oooohh man I didnt even realise that, yeah I was sure it should have worked on server

thanks yeah I can do it without the multicast now

this oddly seems to have fixed the for loop thing but now only two of them have collision (nvm, one event was still multicast and setting to server makes none have collision)

[sinful tree]

I'd still move the loop to be on the server, there's no reason your client should have to tell the server to RPC each bullet for a shotgun as it's more of a burst type effect. I know there are people who do an RPC per bullet fired with automatic weapons, but that's because there is usually a slight delay between each shot.

[oak pond]

collision is done with a sphere trace on tick, so that shouldnt need any extra replication should it?

[oak pond]

yeah I put it all on server and it spawns correctly now

didnt have replicates ticked on the actor itself

[sinful tree]

Nice.... As for the sphere trace on tick, that's not really necessary - you could just add a sphere collider and detect the overlap or hit when it happens.

[oak pond]

no because theres bullet penetration stuff

[sinful tree]

Ah ok

otherwise, you just need to make sure the collision is happening on the server using Has Authority

ie. Tick > Has Authority > Sphere Trace

[oak pond]

oh hang on, the projectiles are stopping when colliding, but shaking around and fighting over where they should be, just seems to be a desync then, need to replicate one of the scripts I made there

well, now collision works but sometimes a bit too late so it goes into walls slightly, but thanks for the help anyway that loop was the main problem

[wooden falcon]

I’m have a pcvr multiplayer game I want to have on quest, I normally built server and client through the windows platform but now that I use the android platform how does it work for the server? Do I build it through android?

[quaint roost]

is net cull broken in editor? i set it to a low value (10k). I walked out of range of another player, the actor dissapeared but when i walked back the actor did not get recreated

[sinful tree]

The distance isn't in standard unreal units, it's a squared value. So root of 10k would be 3.16 units.

Basically need to be on top of it in order for it to become relevant.

[quaint roost]

i see, how did you get 3.16?

[sinful tree]

Default is 225000000.0 which translates to 15000 units

Square Root of 10000 = 3.16

err

100 sorry wtf

Must've had something else in the calculator when I started typing XD

[frigid needle]

hey guy's if i want to know more about the AWS gamelift then which chanel is good for asking question

[quaint roost]

hmm 100, let me try further

[sinful tree]

None really as this server doesn't really handle AWS support.

[frigid needle]

oh okay then if i ask some of question here then it's small chance to get answer right

but still it's multiplayer channel so expect to get some answer i guess

[sinful tree]

Yep. AWS Gamelift is a separate service that's not specifically tied to Unreal Engine itself. If you're trying to integrate it with Unreal, then you'd probably want #cpp if you're having trouble with getting it coded. If it's a plugin you're using that you're trying to use, then you'd probably want to hit up the developer and check if they have their own Discord or support channels as people here may only have limited knowledge of that plugin. Otherwise, you can ask, but yeah, might not get a great answer :/

[frigid needle]

oh okay Thanks bro for information

[quaint roost]

For future searchers: if you think net cull distance works weird (actor not getting recreated when going back into cull distance), it's because it operates off your camera location, not player actor

[thin stratus]

Yop to be more precise it works based on your view location. Doesn't need to be a "camera"

A lot of stuff actually does. E.g. there are nodes that calculate AOE Screenshake based on camera internally. Shows UEs ties to first person shooters.

[errant glade]

Is anyone knows the best course of dedicated server?

[hybrid pecan]

on a listening server is there a way to let the host client spawn a actor without it being replicated to everyone else on the network?

The fact I'm struggling to find info on this is odd, I'm sure tons of people have tried to perform something clientside on a host client?

[dark parcel]

Just spawn it on server but don't tick replicate and net load on client?

[hybrid pecan]

don't tick replicate and net load? where is that?

[dark parcel]

Actor detail

[hybrid pecan]

but I'm also using the same actor to replicate across all clients for other situations

[dark parcel]

well you said earlier you don'tw ant it to be replicated

[hybrid pecan]

not in that scenario no, I think doing this though fixes it

or it appears to fix it

[dark parcel]

did it?

I think that;'s kinda unreliable. If you add delay it will actually spawn the Actor in all clients regardless

[hybrid pecan]

Its not replicating to other clients so yes

if I add a delay it just spawns in its set location

but since its following the users cursor it disappears because thats not replicated to other clients even on the host client oddly.
I mean ideally would not to replicate it on the client period but this seems to be a work around till I can find a better solution. I think running the server as a separate process on the host PC would be the ultimate solution but the most complicated

[upbeat geyser]

Just question to understand, does the server need to know that client pressed on key to look around to change pawn yaw rotation?

[ivory dagger]

no, the server doesnt need to know. there should be an event that executes when you press the button and it can handle everything

[upbeat geyser]

So the SET need to be in event that will be Executes on server?

[ivory dagger]

it should execute on both the server and your local machine

[upbeat geyser]

So something like this? its working just want to make sure this is the right way

[ivory dagger]

yep

[half umbra]

how can i get player name correctly?

server normally get name

but for client is None

with delay works

but how can i do it without delay

[half umbra]

ok, so Client has Controller and Server has controller, so 2 games == 3 controllers

Client Controller is first when player join to server?

and second Controller for this client is on server

[chrome bay]

So the characters' controller will only be valid if it's a local controller. The Player State will only be valid if it's replicated + the controller has replicated it's reference to it.

Clients don't receive other players' controllers nor the servers' controller

Characters already have a reference to the controlling player state, so you can just get that. Unfortunately, since this is Blueprint you have no idea when it'll become valid.

[half umbra]

thanks

[pseudo merlin]

whats best practice for clients shooting projectiles that use projectile movement component? sending a rpc to server to spawn causes a noticible delay on seeing projectile spawn on client, I could spawn projectile on client then send RPC for server to spawn on other clients, but projectiles get replicated to all clients so shooting client would see 2.

[faint parcel]

What is the simplest delegate/event-based way of allowing a UserWidget blueprint to subscribe to changes (add, remove, change of items) of a UActorComponent subclass's FFastArraySerializer class?
I'm ending up with a lot of delegate code and I'm wondering if there is a common way.

What I'm trying out: the UActorComponent has some kind of delegate or event exposed that the UserWidget blueprint can subscribe to. The UActorComponent then itself listens to changes in the FFastArraySerializer subclass.

[winged badger]

you can inject the component as Owner into the FastArray, then broadcast directly from its callback functions

just don't do it in a constructor, and just a non UPROP TWeakObjectPtr<UYourComponent> Owner;

[wooden falcon]

Will an adroid build work on windows server? If I build the client on android and the server on windows, will that work?

[ocean dust]

Hello, all. I still have not found a good solution for my previous issue of Load Level Instance not replicating and therefor stopping my procedural map generation from working for remote clients. Does anyone have an insight into some other ideas on this topic? Thanks!

[worthy wasp]

MP AI Perception - i'm having a LICK of a time getting this TeamId to set right... wondering if someone sees something i'm not:

1: I spawn AIPawn (getWorld()->SpawnActor()...)
2: I set new pawns Team appropriately (see below ETeam enum)
3: AIController::OnPossess SetGenericTeamId((uint8)MyPawn->Team);

This TeamID is ALWAYS 255 when its going through perception phases.... I"ve even gone as far as setting the TeamId to Replicated - thinking it was an MP Replication issue (shotgun attempt at best...) but i didnt expect that to even work in the first place..... What am I doing wrong? The MyPawn->Team is a value of 1 when it hits that function (3 above) but the UINT8 cast is setting it to 255 :/

UENUM(BlueprintType)
enum class ETeam : uint8
{
    Defenders UMETA(DisplayName = "Defenders"),
    Attackers UMETA(DisplayName = "Attackers")    
};

[thin stratus]

Did you implement the generic team interface?

And the getter?

[worthy wasp]

AIController already implements that -
class VIGAME_API AVI_EnemyAIController : public AAIController

[thin stratus]

Oh?

And you override it with your own teamid variable or?

[worthy wasp]

you maybe onto something...

FGenericTeamId TeamId is set to PRIVATE in AIController.h

All readings i've done they make their own FGenericTeamId in Protected scope in their extended AIController class -w hich i've done...

doesnt this conflict?

same name -
FGenericTeamId TeamId;

[thin stratus]

I guess? Why do you need it to be custom

If the ai controller has it

Pretty sure they expose it via the interface?

[worthy wasp]

they expose the function publically - not the variiable TeamID

But i'm also questioning if i need to even override this GetGenericTeamId() - i'm not doing anything in it.... i'm going to remove that to see if that makes the difference.....

AIController.h

    //----------------------------------------------------------------------//
    // IGenericTeamAgentInterface
    //----------------------------------------------------------------------//
private:
    FGenericTeamId TeamID;
public:
    virtual void SetGenericTeamId(const FGenericTeamId& NewTeamID) override;
    virtual FGenericTeamId GetGenericTeamId() const override { return TeamID; }```

yah this compiles...

all readings i've done say that you need to override GetGenericTeamId() as part of the interface -

doesnt look to be a required override tho

[thin stratus]

It is if you put that into any other class I guess

E.g. a character

[worthy wasp]

i get it!

ok

that makes more sense - cuz the parent already had it

[thin stratus]

Since the AI controller isn't replicated most peeps probably have the variable a second time in the character or so

Would need to override the setter in both classes though to keep them in sync

[worthy wasp]

This solved the 255 issue - thanks for helping me think out the box 🙂

[stoic lake]

Hey, I'm working on creating a voice chat system. How can I disable voicechat for a specific player? Meaning that they cannot hear other players?

I'm using the built in VOIP system

For context: this is for a walkie talkie system. I want players who do not have a walkie talkie in their inventory to be able to receive walkie talkie sounds, only proximity chat

[thin stratus]

I know it's now what you ask for, but that Delay loop is realllly shitty :D

But that aside, I'm not sure atm you can do that. The default VOIP system has this Mute functionality I think

But that mutes one player for all others

Not other way round

[stoic lake]

I know, this was just to quickly set things up

[stoic lake]

Alright that's a bummer, thanks though!

[knotty briar]

I see thanks for the answer, it’s better for me to ask instead of search online for an answer that I was looking for but wouldn’t work. I will be developing a mixture in that case using the existing cmc system but for vehicles

Like remake the system

[hollow flicker]

Hello, I am currently trying out the multiplayer stuff on the FirstPersonTemplate. Net mode is set to Listen server with two players.
In the FirstPersonBP, I create a widget on Event BeginPlay, promote it to a variable and set it to viewport (its my HUD).
Now, at one point in the game, im using RPC to call an event on all players which changes their HUD (and therefore accesses the saved hud variable in FirstPersonBP).
If my client fires this event, the HUD changes fine on his side. But when it comes to accessing the servers HUD variable, I get an error because it is apparently "None", even though I did set it after BeginPlay and wouldnt know why it is now None?

Can somebody help me with that and explain whats going on?

[daring gorge]

hello, should the functions triggering safe variables in custom cmc be replicated?

[dark edge]

Hud isn't replicated. Show your code

[hollow flicker]

What do you wanna see

[dark edge]

RPC on

[hollow flicker]

What do u mean

[dark edge]

From the RPC to wherever you do the stuff you do

[hollow flicker]

Alright

The CallFP event gets called from a button press in the HUD

The Print String is already giving me that the variable used to store the widget is None, which later results in an error as described

[hollow flicker]

(event is called by the client btw)

So client presses button in his HUD and fires CallFP

All the screenshots are from FirstPersonBP

This is how the HUD variable is set on BeginPlay, also in FirstPersonBP

[dark edge]

Win Shift S

[dark edge]

show what's before this

you only want to do that on the local copy of the actor

IsLocallyControlled

[hollow flicker]

This is whats before, just template stuff after BeginPlay

[dark edge]

gate that by LocallyControlled

you don't want to do any of that on any copy of the pawn besides the locally controlled one

[hollow flicker]

I put a branch after BeginPlay and checked IsLocallyControlled, but error remains (server hud var is None)

[glacial thicket]

Hi everyone, I am new to Unreal Engine, I would like to know how I can notify the server that I am managing an object. I'd be happy to have any information which can help me.

[sinful tree]

You probably want to make your paddles there pawns that your player controller then possesses.

[fathom aspen]

Well you wrote the name of the function you should use in a comment and yet you use BeginPlay

BeginPlay of Pawn is cursed to get the PlayerController at

[hollow flicker]

I dont really know what you mean, could you explain a bit more in detail?

[fathom aspen]

Use OnRecieveControllerChanged instead of BeginPlay for this

Literally what the comment their says

It's prolly not yours

I falsely assumed it was, but it feels weird that it's there when it's actually BeginPlay

[hollow flicker]

Its the FirstPersonShooter Template

[fathom aspen]

Yeah so it's on Epic

They did the comment part, but left the implementation cursed 😄

[hybrid pecan]

Using SetReplicates seems to be a workaround to run stuff clientside as a server host

[hollow flicker]

Did that now, the error remains though.

[fathom aspen]

I'm not sure what you did

I'm not sure what error you are referring to

[hollow flicker]

I replaced BeginPlay by OnReceiveControllerChanged

[fathom aspen]

With no IsLocallyControlled?

[hollow flicker]

The one I am trying to fix, where the widget variable of my server is None for some reason

[hollow flicker]

Tried it with and without lol

[fathom aspen]

The widget should be valid if you create it and associate with a local player controller

Nothing really fancy

[hybrid pecan]

Its so odd how I cannot find documentation, are listen servers not popular or something?

[hollow flicker]

It seems like after my client spawns, the servers widget variable gets set to None

[fathom aspen]

Well documentation in general is scarce, nothing exclusive to listen-servers

But since you asked, it's not of Epic's interest either

[hybrid pecan]

yeah trying to figure out how to run things only on the client when the host is the client isn't easy, I think I found a work around but I don't think its a great work around

[fathom aspen]

Sounds like you're referring to the Remote pin in SwitchHasAuthority macro and wondering why it doesn't fire on listen-server player at all

I mean yeah it shouldn't

You instead use IsLocallyControlled, IsLocalController

And a bunch of similar functions

[hybrid pecan]

who are you talking to

[fathom aspen]

You

[hybrid pecan]

how would checking if locally controlled help?

[fathom aspen]

Help in what sense?

[hybrid pecan]

being able to run stuff on the host client without it replicating to all other clients?

[dark edge]

That's literally what you're asking for. You want to run something on the OWNING CLIENT right?

[hybrid pecan]

yes. but the host client, is also the server so anything they do is replicated to everyone else on the network

[fathom aspen]

Well they don't really know what they are asking for

Another sad day for the science of question asking

[dark edge]

no, only replicated things are

What are you actually trying to do here

[hybrid pecan]

I'm trying to spawn a actor but locally on each client so they are clientside

[fathom aspen]

Don't replicate the actor just to begin with

[dark edge]

yeah just have the actor not be replicated

[fathom aspen]

And spawn it after the check mentioned earlier

[hybrid pecan]

I'll give that a go

[dark edge]

Or you can have it be replicated but not actually replicate anything. What's the game mechanic?

[hybrid pecan]

Being able to place a actor down but when you select a actor a ghosted version of that follows your mouse, doing what yall said seems to work though

[supple cypress]

What's the best way to check that all clients have connected and have finished spawning pawns after seamless travel? I want to set something up in GameMode to know when to start the match.

[hollow flicker]

Does someone know more about why that might happen?

[sinful tree]

There are lots of reasons why that could potentially happen. You could show more code as to how you're handling the creation of the widgets and when you're accessing it that it shows None, preferably showing the initiating event that leads up to it too.

Begin Play fires on clients and server, so if you're creating widgets there, the server and client could potentially be creating the widget when you may only want it for whoever the owner is of that controller or character, or whatever class it is you're using to create that widget.

If you're attempting to access the widget of a client on the server, or vice versa, that's not possible as widgets do not replicate.

[hollow flicker]

I showed all of the relevant code already in screenshots above. I do want the widget on client and server, so I suppose BeginPlay creating it for each is fine too?

Do you mean I am unable to access other widgets except my own through the server? So an RPC Multicast to, lets say, change a text on the widget for every player, would not work? How could I still ensure that if my client does something, the widget of my server changes aswell? (As the widget of the client is doing fine)

[sinful tree]

Creating on begin play of a character is bad unless you have an IsLocallyControlled check before doing it, otherwise everyone is creating it and if it is just your HUD, you should only be creating it once.
The other problem is that if you're running a multicast on a character, then you're referencing the HUD created for that particular character but since you (hopefully) only created the HUD for the one local player character, you wouldn't necessarily have created a reference to the HUD on the character you're calling the multicast on.

[hollow flicker]

And this missing reference might explain why it gives me "None"?

It does seem like even tho my server does have his hud reference, the client seems to think it is None. But idk

[sinful tree]

Probably. Each character is its own instance of your blueprint. If you create a widget on a specific instance, only that one instance will have reference to that specific widget.
If you create it on every instance of your character, then you'll have several instances of that widget, each referenced on the character it was created on.

So the HUD you'd create on Character1 would be different from Character2

So calling a multicast to do something with the HUD reference on Character1 means you're trying to access the HUD created on Character1.

[hollow flicker]

I thought itd work like this: the code after the Multicast event will be executed on each players instance seperately, and therefore use their own HUD reference variable as created at BeginPlay

[sinful tree]

And it doesn't work that way. When you call a multicast, you're telling everyone to execute something on that particular instance.

[hollow flicker]

Okay, thank you. Now, how else could I achieve this? Basically, client pushes a button, and his aswell as the servers HUD change

[sinful tree]

That is difficult to do when the HUD is in the character as you don't really have a good reference to the local HUD. You can easily get a reference to anything stored on the current player, but to get your own local HUD from a player character, you'd have to do something like, Get Player Controller 0 > Get Controlled Pawn > Cast to your Character Class > Get your HUD reference and do stuff.... It's messy.

This means: Don't store your UI on the character. There is a "HUD Class" that you can set in your Game Mode that gives you an actor that is instanced locally for each player. You can create your own HUD Class, and have the logic in there to create and add the UI to the viewport. You can access your HUD using "Get HUD" anywhere but you still need access to the owning Player Controller, but then you can cast it to your custom HUD class and do what you want to the widgets it has created, but that's still not all that great as you could instead have your widgets read and listen for things rather than trying to push changes into your widgets.

Need a widget to display a player name?
Have an event dispatcher on PlayerState that you call during OnRep of the player name. Have your widget bind to that event dispatcher to read the PlayerName. How does the widget know which PlayerState? You create the widget when a PlayerState joins the game, which you can use the Begin Play of the PlayerState to determine when a player has joined - create an event dispatcher on Begin Play of the PlayerState, have your HUD listen to that event dispatcher, and when you hear it, you can create the widget.

[hollow flicker]

So rather create the HUD in the HUD class and save a variable there? And whenever you need it, get the HUD, the variable, and do stuff?

[sinful tree]

That would work better, yes, but again, ideally you're not forcing the data into the widgets - the widgets just listen for the data to come in.

[sinful tree]

Doing it this way means you still need to do "Get Player Controller 0" > "Get HUD" > "Cast To HUD" > Do the stuff.

The benefit is that you're no longer trying to reference the HUD that you've stored on a particular character.

[hollow flicker]

Can you explain why Cast to HUD? I thought if id store a variable of it, I could just pull that out and call events or stuff

[sinful tree]

I'm talking about a HUD Class.

[hollow flicker]

Oh okay

[sinful tree]

So within the HUD Class, you'd create your actual HUD Widget.

[hollow flicker]

Yep just got confused with the terminology for a moment lol

[sinful tree]

Unreal should change the name to "Widget Manager" class 😛

[hollow flicker]

Why is networking so hard

[sinful tree]

It's more having to understand Object Oriented Programming and realizing that those objects can exist in more than one place.

[hollow flicker]

Out of all the programming ive ever done, networking was the weirdest stuff to me

It often went wrong when the code looked totally fine

[sinful tree]

Doing something on a particular Object means that object. Not on others that are like that object. If you want all the other actors of that particular object type, then you have to reference them and ask them to do it too.

Networking adds the additional headache of understanding who is in control of the object, and on which instance of the game you're calling the instruction on.

[hollow flicker]

Its like you do stuff but it gets received totally differently and i dont know why

[hollow flicker]

Yeah in UE5 its not the easies to grasp, but even something low-level like sockets is just...weird idk

[sinful tree]

Sockets is basically the same thing.
Server is started.
Server sets up timer to only stay active for the next hour.
Server starts waiting for connections.
Client connects to server.
Server stores reference to the client object that joined in an array and sends a heartbeat every so many seconds if nothing is received to know if the client is still connected.
Client sends instructions. Server receives, does what instructed, sends back response to the client object that sent the instruction.
Client receives response back about status of instruction.
Server detects client hasn't send anything in 20 seconds, heartbeat sent.
Client receives heartbeat and notifies server it's still alive.
Server receives heartbeat from client.
29 minutes (and many heartbeats) later....
Client forcefully disconnects.
Some seconds later...
Server sends heartbeat, client object is no longer valid > Server removes client object from array.
30 minutes later...
Server timer is up! Server gets reference to all connected client objects, loops through them and tells them goodbye, disconnecting them.
Server process shut down.

[hollow flicker]

And the worst part is how once it all works perfectly fine on ur local network, u try it on a real wifi and it all breaks down

[sinful tree]

That's thanks to latency mostly. What my computer sees isn't what the server may see whether we're 5ms or we're 300ms latency away from each other.

The server is always in the future compared to my computer.

[sudden condor]

Best way to say "hey everyone, possess this specific camera actor in the level" in blueprints? I want all my players to enter the match into a short preround where they can see the map. I was thinking each PlayerController possesses it during Begin Play, but I am unsure of the best way to tell the PC what to possess. If hardcoding the camera actor ref into the PC is an option, that should work fine.

[loud cove]

what's best practice to distinguish between a simulated proxy and an autonomous proxy, e.g. when adding components to my pawn that will only ever be active/visible for the autonomous proxy?

[latent heart]

You can't really have multiple players possess a single actor (especially if it's just an actor and not a pawn!) You could set it as their player controller camera manager's view target, though, or something.

[loud cove]

i can have the same exact class for both, simulated and autonomous proxies, and just disable/hide some components at runtime when the pawn isn't locally controlled. but is this the way to go?

[sudden condor]

You're right, that's what I want. View target. That slipped my mind, thanks.

[latent heart]

That's basically how, say, player mesh vs arms mesh works for things, so why not?

You could even add the local-only components dynamically on begin play if it's locally controlled.

[loud cove]

i guess it works ... it feels a bit messy. In theory the locally controlled pawn could inherit from the general pawn and explicitly add stuff

[latent heart]

Or add them via the player controller when you acknowledge possession?

[sinful tree]

Check what the actor's netrole is (Get Local Role and Get Remote Role can help you determine this in Blueprints)

[loud cove]

that's interesting, sure. it limits my ability to use the editor to configure the components, though

[latent heart]

You're posessing things in the level already? Rather than spawning new pawns?

[loud cove]

but well, my question is about best practice: there is nothing wrong with adding stuff and hiding it for not-locallycontrolled pawns. so that's an answer. thanks.

[loud cove]

no, but I can use the blueprint view to set up the camera and some cockpit stuff in the editor

[latent heart]

Ah. Yeah.

[loud cove]

and those cameras and the cockpit isn't active/visible for pawns that are not locally controlled

[latent heart]

Not sure about best practices, tbh.

It seems just like a very advanced version of player vs arms mesh, though.

[loud cove]

i will organize my code a little bit and address this even by putting comments // locally controlled stuff here: ... to reduce the cognitive load. I wouldn't mind having stuff in two distinct classes - but that is not strictly necessary, either.

[sudden condor]

The new learner experience of looking back at your code from even just a week ago:

I spawn my players with a for loop, during which I give them a killfeed widget, and I store all the widgets in an array, that I iterate over whenever I broadcast a kill event....

[scarlet temple]

HIII^^ any one know of any good guides to set up multiplayer with google play services? been looking but i cant find anything

[wooden falcon]

Hey, I’m building my dedicated server on windows and my client with android. Does that work? Or how do you get the server for an android build? Anyone knows?

[hoary spear]

What quantum computer you got laying around lol

[sinful tree]

Maybe I should've said my computer is always in the past compared to the server? That way it doesn't break causality!

[hoary spear]

Indeed x)

What's the common way of doing server logic if not dedicated server ?

seems the server doesnt get onRep's

(which makes sense, but ruins the setup )

i keep on adding stuff like this to 'fix' it but it feels rather dirty

if (GetOwningActor()->GetNetMode() != NM_Client)
{
    SkillPointsChanged.Broadcast(GetAvailableSkillPoints());
}

[sinful tree]

You can just call the OnRep function manually when setting the value on the server.

[hoary spear]

Still feels kinda dirty, but cleaner than what i got today i guess

[delicate igloo]

What is the absolute first thing I should learn when getting started with multiplayer?

[ivory dagger]

this
https://cedric-neukirchen.net/docs/category/multiplayer-network-compendium

gives a good overview about the framework

[delicate igloo]

Thank you so much

When should I start thinking about multiplayer?

Seems like something I should consider integrating early

Or is that wishful thinking

[ivory dagger]

i consider myself a beginner too so dont take my advice as the absolute word, but i learned BP programming for about 18 months before jumping into MP

[delicate igloo]

Did you come from a coding background?

[ivory dagger]

no, started with unreal BPs

[delicate igloo]

Okay I’ve only been in unreal for a few weeks haha

[ivory dagger]

maybe try to make a few games by yourself to practice, then start MP.

https://www.youtube.com/playlist?list=PLzykqv-wgIQXompUswD5iHllUHxGY7w0q
i followed this playlist, it gives a introduction about how to use what you learn here https://cedric-neukirchen.net/docs/category/multiplayer-network-compendium in an actual game

[delicate igloo]

I get that haha but sometimes wanting to learn something overrides that safety 😜 just gotta jump in sometimes

I made a 2D open world game onetime in html5/typescript and adding multiplayer after the fact was the most annoying thing I did

[ivory dagger]

its ok that way too but u might have hard time understanding some concepts

[untold rose]

Is it a good idea to have interaction line traces to happen on both the client and server?

That did cross my mind. Is there any reason why a line trace on a server wouldn't hit anything but does on the client? I currently have a line trace that happens on both the client and the server but the server side doesn't actually hit anything except for the controlled character (listen server).

The line trace itself it pretty standard.

Yea, i think i've just figured it out. The line trace goes from the camera but I don't believe its rotation gets updated so it never actually hits what the client is looking at.

@whole grove thanks for the help, I just had get the forward vector of the control rotation instead of the camera itself. (as this is what the camera uses)

The line trace is running just server side now as well and all seems to be working as intended.

[twilit radish]

Can't even comment on why those plugins are awful without the message getting removed 😔

[urban palm]

@twilit radishyou are free to share your opinion, the removed messages were about a behind the scene request from someone to get an illegal copy of the plugin, which is obviously against the #rules

[twilit radish]

Oh, my apologies if it came over that way. I was referring to the mod ping message that got removed, I wanted to comment on it 😅
I totally understand the initial message getting removed.

[woven basin]

sorry, I deleted my comment because the original message was removed, so it didnt make sense in isolation 🙂

[twilit radish]

All fine lol. It's not an issue in the first place I just wanted to say those plugins are often massive security leaks haha.

Those MySQL connectors to Unreal / BP plugins yeah.

There are multiple. Not sure which one it was 😛

[hollow flicker]

Hello, in my FirstPersonBP, I am calling an event through an event dispatcher. This is replicated via RPC Multicast.

In my Level Blueprint, I am binding that event dispatcher on BeginPlay to a custom event. This custom event then gets called appropiately.

Now, when the client calls that event, it all works (e.g. Meshes in the level change), but it only works on his side. How could I replicate this, so that my server will also see the changes and be affected by them (so that their level changes aswell).

(Net mode is Listen Server with two players, using the First Person Template project)

[twilit radish]

If all you're doing is executing the multicast then my assumption here would be that your client is directly calling the multicast. Clients are not allowed to execute those as only the server may do so. In that scenario just make a RPC for the client to the server and then have the server execute the multicast.

[hollow flicker]

Oh yes I am doing that already, sorry

In the FirstPersonBP, when the event gets called, it first goes to a "Run as server", and then to a Multicast which calls the events in the Level BP

I believe I might have to do some similar replication in the Level BP, but I am really not sure how?

[twilit radish]

Have you tried checking where it exactly doesn't work any more? E.g. printing messages attaching a debugger?

If the multicast is inside the actual level blueprint it self then it isn't going to work yeah.

[hollow flicker]

The events seem to be binded properly on BeginPlay in the Level BP. And the call to those events through dispatcher in my FirstPersonBP is also replicated with the Multicast like I said. Only issue then seems to be that the actual event in the Level BP which is binded, only fires on the client.

Events binded in Level BP, seems to be replicating fine

Events being called in FirstPersonBP, also seems to be replicating fine

The actual events now in Level BP, only executed on client (not replicating)

[chrome quest]

Do people still do stuff in the level bp?

Fair point

[hollow flicker]

Isnt that the only way to change and do stuff on my level?

[twilit radish]

The level blueprint is not replicated. There's absolutely no way that the multicasts etc. work. Even if it was replicated then the client still would not have ownership over it.

[hollow flicker]

What other ways are there to then change stuff in my level?

[chrome quest]

Game mode, game state, find all actors of class, anything but the level bp

[twilit radish]

Use any other actor that is actually replicated. The GameState for example. If this is being used on a specific actor have that actor do the change.

Also this in specific does not seem like something you want to do with a multicast. This seems to be "state" you're changing with them. If a new players joins they will not have the correct state of whatever the light is in 🙂

[chrome quest]

What you want is OnRep_

Where's that link for onrep vs RPCs?

[twilit radish]

uhh..

Which one? The article Vori made?

[chrome quest]

Yeah, that one

[twilit radish]

https://vorixo.github.io/devtricks/stateful-events-multiplayer/

[hollow flicker]

Okay, thank you all very much! Gonna get to work now

[oak pond]

when testing enemy ai in multiplayer, how do I know its like - actually working? currently ais can see and target both players with no desync, but like is that just coincidence? does it just happen to work because or do I need to see if theres any problems Im not sure how to even check

and also when shooting at enemies with projectiles, they take damage on both clients, but sometimes only on one if it happened too fast or something, so I would set up replication for the damage events but that seems wrong too because it already kinda works

but Im not sure what I need to do since the projectiles are replicated, but enemies dont always take damage on both clients, but I imagine replicating it could cause it to happen twice or something

oh good start, its already unplayable on the "Bad" preset, cant even jump and stuff even though thats just regular replicated events

good point I didnt think about replicating the actual hit in the projectile

I mean Ive been doing this for years

should I really though lol, seems like every time I do this its as if Im a begineer

but should I expect it to be playable on the bad preset?

Ive never worked with ai specifically in multiplayer

yeah with my other project I was prioritising the clients gameplay and then just doing all the replication separately, but I know this would be horrible for any kinda pvp

but that was custom movement too, with default charactermovement component it seems you cant take any shortcuts like that even if you wanted to

man I hate doing this

on Average you can play pretty much fine but lag behind a lot for the other player, even though this is mostly default movement stuff

at least it doesnt seem to completely fall apart

this is one thing that never seems to get easier

[woven basin]

With Rider, if I launch my game in Debug (so the debugger is attached), I can obviously stop on breakpoints etc if I play the game in the editor.

And if I launch a second player from within the editor I can also stop on debug points when it is "run under one process = true". But obviously I really want to test it as seperate process. So I change "run under one process = false".

This spins up another process, and in rider I select "attach to process" and select the new second client. Rider says Debugger attached to process 6752 - Debugger detached - so it seems like it should work.

But the breakpoints are not working.

What am I missing?

Is there a better way to debug clients and listen servers as seperate process?

[quartz iris]

How could I make it so player 1 spawns in a specific location, as well as player 2 doing the same but in a different location?

[oak pond]

just place playerstarts

[quartz iris]

no no they spawn on each other and player 1 for example doesn't always spawn in a certain location

[chrome bay]

Add a tag to them, and override ChoosePlayerStart in your gamemode to use specific ones with a given tag

[quartz iris]

So on event begin play on the player set tag to player state num

[chrome bay]

No. Override ChoosePlayerStart in the gamemode, and search for a player start with a specific tag.

E.g. "Player_1", "Player_2" etc.

Not 100% sure ChoosePlayerStart is exposed to BP but it might be

[quartz iris]

I don't think this is it

I already have my default pawn class set

I'm just looking for a way to spawn a certain player in a certain player start

Is it not this?

[hollow flicker]

Now I got the following problem: Through an RPC Multicast in my FirstPersonBP, the event is being called on my GameState. This event gets executed properly for both client and server, and involves deleting an actor. The actor is deleted for both players, but at the end, im getting an error in my GameState, saying it accessed None trying to delete the actor (that has already been deleted for both players?). Does someone know what might be going on?

[woven basin]

You wouldnt RPC multicast a delete.

You get the server to delete the object, and the object itself is is replicated, so the server will tell the client to delete it via replication

[quartz iris]

Maybe @sinful tree could help with this?

[thin stratus]

@grand kestrel I just noticed that the Movement Comp example doesn't really have a proper MoveContainer example or?

Neither ServerResponse nor ClientMoveData

[fathom aspen]

Believe it or not, the level BP is replicated by default, so you can theoritically multicast there just fine

[twilit radish]

Sorry what

[latent heart]

The one useful thing for the thing that should never be used.

[twilit radish]

Why. Just why.

[twilit radish]

no

[fathom aspen]

Haha, yeah it's just w/e

I was never able to find an answer on to why it needs to replicate, but it's missing all the elements an actor needs to be replicated

I bet it was always like this since 4.0

[twilit radish]

It's not even an actor though. The level Blueprint "self" is an ULevel.

[fathom aspen]

Nah it's an actor

AScriptLevelActor I guess

[twilit radish]

🤔

I mean I guess that does make more sense now that I think about it.

But still. Whyyyy

😂

[fathom aspen]

My only theory is that it was used for scrubbing in UT and they had some replication code that they needed to carry over to the DemoNetDriver

But that's just theory

[twilit radish]

A game theory! See you next time.

Alright sorry had to do it 😆

But yeah.. Even then I still wouldn't use it. It's just an awful way of doing things lol.

[fathom aspen]

I argued if I could turn off replication on it, but it could break things, and I'm not ready for it

[thin stratus]

I just the LevelBlueprint once

And for that I extended it in C++

And that was because the Game had different settings per Level

So I placed the Settings in the LevelBP

It worked and kinda made sense

But that's all I ever needed it for, aside from debugging

And you might be able to just use WorldSettings anyway

But I think I didn't know about that back then

[fathom aspen]

Either that or accessing specific level actors for w/e reason or some level sequence stuff

But yeah I find it rare to need to use it

[twilit radish]

The good old classic "This isn't documented so I could 'technically' turn it off but it may break things quietly" 🤣

[woven basin]

https://twitter.com/RobinVanina/status/1693991294954250479

Robin Vanina (@RobinVanina)

Are you testing your multiplayer game in unreal engine?
Make sure to also test conditions where not all clients are joining at the same time!

You can easily do that by enabling the "Allow late joining" feature 👇🔥

#unrealEngine #gameDev

Likes

131

▶ Play video

Twitter · Aug 22, 2023, 2:19 PM

This is a particuarly awesome feature. I was just testing it out now, works brilliantly

[thin stratus]

If I start a RootMotion Montage in the CMC, while making sure Server and Client have the same Transform, should that cause corrections o.o

[hollow flicker]

Hello, how does connecting and all that stuff work with Listen Server? If I press play now, it just spawns me and my client in, but how would I do things like, setting up a menu where you see servers or can create one, and then spawn, and another person can see that server, connect, spawn aswell? Does anyone have resources on that?

[elder lynx]

Hi, Does anyone know about if we want to run a timer that is synced between both client and server what will be the best way to do it and that way should be cheat proof also?

[sudden condor]

Idk about cheat proof but I run the timer on the server and give clients the handle

[thin stratus]

If you want to see a List of Servers that are hosting, then you need to utilize an #online-subsystems (like Steam or EOS) and utilize Create/Find/Join/Destroy Session(s), where a Session holds the information to connect to the Server.

Without an #online-subsystems you can only connect directly to a known IP and the host has to open ports.

[hollow flicker]

That would be enough. Do you know some resources or guides regarding that?

[elder lynx]

What do you mean by giving handle to clients?

[thin stratus]

Not really, google is honestly your friend here

[upper lily]

session search result is always empty. anyone have any fix?

UE 5.2 / STEAM

sessionSettings->bUsesPresence = true;
sessionSettings->bUseLobbiesIfAvailable = true;

Both lines already there.
Able to create sessions but when trying to find sessions it is always returning 0 ( Checked in debug and as well as build using debug write on screen )
Image
SCARBLAZ — Today at 9:26 PM
am testing on 2 different laptops, different steam accounts but on same internet network. idk if this is helpful

can anyone help?

[hollow flicker]

Alright, thanks!

[thin stratus]

You can host a game with the OpenLevel node and passing ?listen in the options. (if a Player should be able to host) or you need to build the Engine from Source (gitHub) to build a standalone DedicatedServer for your game.
If you have the IP and the Port is opened properly, you can either use the console (for debugging) or in BPs use "ExecuteConsoleCommand", where the Command is open <ip:port> , e.g. open 127.0.0.1:7777

[sudden condor]

When you use a set timer node it outputs a handle object. This is basically a reference object to the timer. If you give it to clients they can see what the timer is doing (time left/passed, is paused, completed, active, etc.)

[elder lynx]

Got it, thanks @sudden condor

[tawny talon]

Hey nice ppl, i have a question about multicast and rep notify, not quite sure if i should post it here or not, so I'll describe my question fast and if it should not be here i would delete the post.
It's about the rep notify and multicast event related to the networking example regarding the treasure chest.

https://docs.unrealengine.com/4.27/en-US/Resources/ContentExamples/Networking/2_4/

So based on this explanation, multicast event would be used to play effect, while the rep notify variable will be used to make the chest stay at an opening state.
This is all good. But in my scenario, there is a rather complicated "chest open animation". What i would like to have is:

1. When the player first opens the chest, play the effect and this complicate animation;
2. When the player comes back (become relevant), make the chest "open" immediately without the complicated animation.

It seems logical to extend the multicast event to play both the animation and the effect. Yet since the rep notify happens as well (almost at the same time when the multicast event happens), this rep notify would somehow force the chest to stay open, which seems conflicting with the multicast event where it wants to slowly open the chest.

Is there any good way to work around this conflict?

[magic furnace]

you multicast the animation

once it finishes

you onrep that it is open

otherwise you have conflicting code

so first the multicast happens, the chest opens

to keep it open forever, you set some variable that is onrep to open

[tawny talon]

Make sense

[magic furnace]

but first you wait for the animation to finish

[upper lily]

guys anyone have idea of this issue??

[thin stratus]

You can make that a bit more complicated by skipping the OnRep result if it means the Chest is open while you are playing the open anim

Cause it might just replicate faster back and the anim is suddenly skipped

[magic furnace]

a lot of lazy devs would just keep it an onrep lol

since honestly, you load in, all the chests in your relevancy range open

but it happens while loading, which is how a lot of games just don't care and leave it like that

[thin stratus]

If you walk out and into relevancy range, you'd notice it though

[magic furnace]

depends

usually it's high enough that well, you don't really care

example: not really networked but in baldurs gate 3 this happens

it plays the animation still

right as u load the last save

[tawny talon]

Yes. The actual case for me is that my chest is not really a chest, but a collapsing rock where i kinda want to let the playdr watch the animation in the first run, but don't play it again when next time the player approaching

[soft cape]

Does anyone have suggestions on why OpenLevel works for Host but not the Clients? Clients most of the time just timeout, so I'm thinking that the host needs to do something before the clients are notified to load level.

[thin stratus]

What are you doing?

And what are you trying to achieve

[magic furnace]

Hey I've noticed that on my dedicated server in the session settings my build ID is 0?

doesn't this correspond to the project version?

[soft cape]

Host creates a party, others players join the party, then the host initiates a CreateSession() and load into a "Lobby" level with a widget selection

Pulling the other party members into the level as well

[latent heart]

Why create 2 types of session?

Surely a party is just a session that hasn't progressed to a lobby?

[soft cape]

Yeah I'm not too sure about that. Most of the code I'm working with isn't mine

[magic furnace]

great chance to correct that idea and just have everybody join 1 session

[latent heart]

I guess it could make sense if there's the option for randoms to join your lobby, like CoD or whatever.

[soft cape]

That is the idea, that I am going for

[thin stratus]

That's a pretty involved thing

MainMenu Parties, like OW, CoD, CS, FN, etc. are done with BEACONS in UE

Which require C++ unless something changed

They are lightweight connections that don't actually join a level

They use PartySessions (which are different from GameSessions in theory)

And if you use something like Steam, you can't actually be in both at once, so you also have to manage recreating the Party afterwards etc.

If you don't want to deal with that, you'd only have the option to actually connect to a Level (e.g. a Lobby) and then SERVER TRAVEL (seamless!) to the Gameplay Level

OpenLevel isn't used anymore after connecting unless you want to disconnect.

Server needs to call ServerTravel <mapname> to take clients with it

[hollow flicker]

Hello, in my GameMode, on PostLogin, I am casting to the GameState and run an event. This event on the GameState checks if two players are connected, and then does stuff. This functionality is only happening on the server though, and not replicated to the client. Why is that the case, and how could I still achieve the desired functionality? I suppose it doesnt really work because the GameMode only exists on the server? But I would need PostLogin to check the amount of players whenever a new player joins, or are there alternatives?

[bronze glade]

Hey everyone! How do I enable seamless travel in PIE? I need to use PIE for a plugin I am testing with multiplayer. I see this warning:
LogGameMode: Warning: ProcessServerTravel: Seamless travel is disabled in PIE, set net.AllowPIESeamlessTravel=1 to enable.

But when I enter it, I get a warning that 'set command cannot be used in editor' so is there just nothing I can do?

[sudden condor]

You could try calling "execute console command" in code

[dark edge]

Why do you need PIE when you can just launch?

[sudden condor]

This travel works, but "copy properties" isn't being called in the PlayerState. I got this indirectly from a guide so I feel like it should be able to work.

[bronze glade]

That's what I did to get the original error

[sudden condor]

ah well idk then

[bronze glade]

I am using a plugin for multiplayer and it only works in PIE I guess. Unless I package and build but I don't want to do that for every test

[dark edge]

You can launch without having to package

[sinful tree]

Try playing as standalone game?

[dark edge]

not much slower than PIE

[sinful tree]

You can even launch your game from a shortcut that does something similar without packaging.
Target:

D:\UE_5.2\Engine\Binaries\Win64\UnrealEditor.exe "path to your uproject file here" levelnamehere -game -log

Start in:

D:\UE_5.2\Engine\Binaries\Win64

Change the path to Unreal based on where you installed it.

[bronze glade]

Okay I'll try and figure out how to do it with standalone. Thank you all!

[dark edge]

yeah i love doing this for testing

[hollow flicker]

Can someone educate me on this?

[sinful tree]

You can use BeginPlay of PlayerStates on clients to know when a player has joined the game.

You are correct in that GameMode only exists on the server, so when PostLogin is called, only the server is executing all the following code.
The alternative is to have your GameState function be called as a multicast - the only trouble here is if you're using playerstates at all then there's no guarantee that the playerstate of the joining player has been replicated when you receive the multicast.

[sudden condor]

When switching levels, at what point can I be assured that this call will yield a non-null value in the PlayerController?

https://wizardcell.com/unreal/persistent-data/#gameframework-objects-creation-order-and-calls Useful reference for this

[sinful tree]

Whenever that Camera Actor is created. If it's something placed in the level, then it should be accessible immediately. If it's something that is spawned, then it should be when it gets spawned, unless it is replicated in which case then when it begins play on a client.

[sudden condor]

It's placed in level (should have said that), but I still get a bad value even when I wait until my client receives it's replicated PlayerState

[hollow flicker]

If I tried this correctly, replicating my event in the GameState as Multicast, and calling that event from my Gamemode, does not fix the issue and still only works on the server.

[sudden condor]

Also the game mode appears to be invalid at the same time, but I'll have to do some more investigation to see if that's just user error (probably is)

[twilit radish]

The GameState exists for everyone though.

[sinful tree]

GameMode only exists on the server, you can't access it on clients.

[sinful tree]

And I'm testing it myself now, on begin play of player controller, getting ref to a placed camera actor is valid on client.

[sudden condor]

That works when I play the level directly, but I'm having trouble when I'm loading it from the lobby. Not sure if the situation was clear (my bad) but I am transitioning to a new level when this happens.

[sinful tree]

You're probably running into another problem in that the GameState also needs to replicate to clients.
So calling the multicast before the clients receive it, which can happen on PostLogin, would mean the client wouldn't get it.

[sudden condor]

A little weird it lets me call this in the controller then. Guess I have to access it through the state?

[dark edge]

You can call it but that doesn't mean it'll give you anything good

PlayerController exists on server and owning client

[sudden condor]

Yeah, the editor should probably say something about it though lol

[hollow flicker]

How could I prevent this?

[sinful tree]

It's a static funciton meant to be accessible anywhere in your code - it's an ease of use kinda thing. A player controller doesn't mean "client" as that player controller will exist on both the server and the client, so depending on when you call that function (ie. running on the server) it can be valid.

[dark edge]

Miata Onrep
Is
Always
The
Answer

[sudden condor]

I hope this gif works

dangit

[sudden condor]

Still having trouble over here though

[sinful tree]

Same thing... Using servertravel, player controller still gets a valid reference to a placed camera actor in the level on begin play.

[hollow flicker]

Besides always checking the playercount on PostLogin (or maybe OnPossess), how could I make sure that a certain event does not fire on BeginPlay (when the first player joins), but waits for the second one?

[sudden condor]

Weird...I am definitely using server travel though.

[sinful tree]

You use postlogin for the server to know.

The server can set an OnRep as adriel said which should probably be in the gamestate, that onrep can then drive the logic on clients.

It can be a simple bool, "PlayerLimitReached" -> Set true -> OnRep fires -> Things happen

[hollow flicker]

Can you guide me to some resources on OnRep? Never heard of it

[sinful tree]

Lots of pins in this channel that go over it.
It's a means for a variable to call a function when it receives a new value, usually when a replicated value gets received.
You can mark a variable as OnRep by setting its replication setting to RepNotify - doing so will automatically create a function in the class that will be called when the value changes.
You can put whatever logic you'd like in the OnRep function, including doing anything based on the new value of the variable.
This also lets you drive stateful logic, meaning you can set the value before the client knows about the actor that contains it, but when the client finally does know about the actor, they'll receive the replicated variable and the OnRep will fire, causing the logic required to execute when received.

Just like standard replicated variables, you need to set the variable on the server if you want all clients to receive the new value.

[hollow flicker]

Thank you very much, its working now :)

[candid mulch]

I have an rpc set up that plays a anim montage but there are constant desyncs that happen

this was from a dash root motion montage

is this fixable???

[haughty estuary]

First time trying out multiplayer but having trouble playing my test level. When I set the net mode to play as client (expecting a dedicated server to start up) then I get an error message pop up Couldn't Launch PIE Client If I try running in listen server mode it launches as expected when there is only one instance but If I try playing with two clients I get the same error message. Anyone have any ideas what this could be?

[hollow flicker]

Hello, is there any way to be able to host a game on my PC so that another client can connect to it/join me, without me having to forward ports? I am sadly unable to do so, therefore I would somehow want to circumvent it. When I did some networking in Python, I used to host a server via ngrok. Is there anything similar I can do here?

[dark edge]

You need to do NAT punchthrough somehow, typically that's handled by Steam or EOS or whatever

[sinful tree]

This is likely the bit of code that is throwing up that message, and it's from the GameInstance.

        if (EditorEngine->Browse(*WorldContext, FURL(&BaseURL, *URLString, (ETravelType)TRAVEL_Absolute), Error) == EBrowseReturnVal::Pending)
        {
            EditorEngine->TransitionType = ETransitionType::WaitingToConnect;
        }
        else
        {
            return FGameInstancePIEResult::Failure(FText::Format(NSLOCTEXT("UnrealEd", "Error_CouldntLaunchPIEClient", "Couldn't Launch PIE Client: {0}"), FText::FromString(Error)));
        }

The if statement sounds like the engine is attempting to travel, but its failing.
Have you tried restarting the engine and your computer? Make sure there isn't any VPN stuff interfering?

[haughty estuary]

Thanks @Datura, I've tried restarting the engine and double checked VPN is not running but still got the same error message. I've managed to get a bit further by disabling the Run under one process multiplayer option in the editor preferences. I can run in listen server mode with more than 1 client but it takes forever to load the second client, not sure what's stopping both clients from running in the same UE process 🤔

[sudden condor]

@sinful tree To elaborate from earlier, here's how I find my camera in the world. I can confirm that if I place a one-tick delay before the "get actor" it works perfectly. Might just end up doing it that way if there's no simple solution. Idk why yours works but not mine.

[hollow flicker]

How could I do that? Are there any other solutions maybe?

[sinful tree]

No reason to pass "Get Game Mode" here. You can just call "Get Game Mode" in the controller.
You're also doing this a bit oddly as you're crossing whether you're wanting to know if its the server with the remote activation, so then a local playerstate could potentially be calling "Initialize Tank Player" when you maybe don't intend for them to be doing so?

I can't really comment more on the setting of your camera variable there - You'd need to show more of Initialize Tank Player function seeing as you're potentially setting that variable on both server and owning client.

[sudden condor]

I thought we had this whole discussion earlier as to why I shouldn't be calling get game mode in the controller :P

[sinful tree]

You can call Get Game Mode anywhere. A player controller isn't a client. It's an actor. That actor can exist on the server and the client.

GameMode is also an actor, but it can only exist on the server, so if you attempt to Get Game Mode while running on the client, it will always return null.

[sudden condor]

Yeah I just thought it would be easier to pass it in and avoid any ambiguity

[sinful tree]

There's 0 reason to pass it. If anything it'll probably confuse others as you're indicating that there could be some Game Mode requirement to the function, but then you're also calling that function on a client in which the game mode cannot exist.

[sudden condor]

Here's the whole event, not sure how it's relevant though. Unless you mean the event settings. I know it's shitty lol but I'm trying to figure out this camera thing before I clean it up.

[sinful tree]

And here's part of the problem...

You're calling this on a client, Game Mode will always be none.
So if Game Mode is none (which it will be on a client), the cast fails. The cast fails, you're not properly getting your actor variable set on the client if you're attempting to access the variable on a client.

[oak pond]

I have some hud effects for when my players hit an enemy, but how do I reference back to that hud in multiplayer? when spawning the bullet projectiles, I got the instigator and set that as the player who fired, and got the hud from there, but its invalid in multiplayer

[sudden condor]

I thought these were actions that the server didn't need to know about, I'm only sending info one way. The cast isn't failing if I send it as an arg, but the camera still screws up.

So do you think it'll resolve if I run on server

[sinful tree]

Game Mode only exists on the server.
You are calling the "Initailize Tank Player" event on both the server and the client.
Only the server has a valid object it is passing into the cast, so only on the server it succeeds.

[grand kestrel]

I'm not sure. Honestly I've been using it for a while and haven't had to touch it in a long time so I've almost forgotten what's there 😄 Is there something you want to PR maybe?

[sinful tree]

Red Line = Server execution path
Blue Line = Client execution path

[sudden condor]

I understand all this, but I'm not grasping how it affects the camera. The camera is being set, just a bit too early. And as I understand it, setting it on the client's state begin play would set it even earlier.

[sinful tree]

Your issue your saying is the variable is set to none.

It's not being set to begin with.

Only on the server is it being set.

[sudden condor]

It is set if I delay it one tick, like I said

[sudden condor]

This code I sent works. It's just shitty.

[haughty estuary]

🤔 Created a brand new blank project, changed nothing and straight away got listen server mode running with 1 host 2 clients no problem so there must be something wrong in my project.

[sinful tree]

It cannot work in multiplayer. For clients calling this event, it stop here. Nothing beyond this gets executed on a client.

[sudden condor]

Oh I see. Thanks.

[oak pond]

so how is generally the best approach to reference the player that caused damage from a bullet actor

[sudden condor]

Not passing in the GM makes binding the killfeed event kinda ugly though. Oh well.

[sudden condor]

Instigator pins

[oak pond]

yeah thats what I did

[sudden condor]

Then I don't see your question

[oak pond]

cast to thirdpersoncharacter from instigator, got the hud from that, but its invalid in multiplayer

I said that

[sinful tree]

And that's also because you're running into the problem of creating UI while running on the server for that particular playercontroller which you probably don't need to do on the server.

[sudden condor]

Ah my b

[sudden condor]

Yeah I've been moving everything into the HUD class bit by bit, but I was hoping I could get this working first. Guess I was putting the cart before the horse though.

[sudden condor]

You shouldn't be grabbing other people's HUD in MP. Just cast to the character and then run something on the character to interact with the HUD.

[oak pond]

...that is a good point

[sudden condor]

It's basically the same mistake I'm making right now lol

[sinful tree]

So I guess you're trying to make like a hit indicator to signify that the bullet the player shot hit an actual target?
You'd pass the character that shot the bullet as the instigator on the bullet like you said you're doing.
Create a "Run On Owning Client" event in your character - I'll name it "TargetHit"
On Hit In Bullet, cast the instigator to your character class > call TargetHit > Have that grab your HUD and make it display what you want.

[haughty estuary]

Fixed 🤦‍♂️ No idea what was going on, ended up deleting all built files leaving just the Content, Source and Config folders then copied over the newly generated uproject file to my existing project (I disabled quite a few plugins in my project). Worked as expected after that, not sure which of the two was the problem (disabled a required plugin or bad binary/cached data.

[oak pond]

I just did that, but now it STILL wont get the hud, even doing it from the player itself, yet only multiplayer has this problem

this even should have nothing to do with multiplayer I dont get it

[sudden condor]

Your PC can't get its own HUD?

[oak pond]

not in multiplayer

[sudden condor]

o.O

Can I see how you're grabbing it

[oak pond]

just in begin play

and the hud itself functions completely fine

[sudden condor]

I was hitting this a few days ago. HUD isn't valid at PC Begin Play.

[sudden condor]

https://wizardcell.com/unreal/persistent-data/#gameframework-objects-creation-order-and-calls

[sinful tree]

When talking about the HUD in that document, WizardCell is talking specifically about the HUD class.

Creating a widget and calling it HUD and adding it to viewport on beginplay of PlayerController is fine, but you should make sure it's only being created on the owning client playercontroller.

[sudden condor]

Crap I didn't notice he was using a widget, my b

[sudden condor]

Using a HUD is useful though because it compartmentalizes all the graphics code into one place where you don't have to see it all the time.

and it's only run when/where needed

[oak pond]

I never even knew that was a different thing

how does this make any sense anway, its literally adding the hud reference to viewport, so it clearly cant be invalid

[sudden condor]

Try printing the value of HUD using the "build string (object)" node at various places to check its validity. Unless you know how to actually debug in BP, then do that instead lol.

[oak pond]

yeah I tried that, it just gives me the name of it as Id expect

[sudden condor]

even when running the code for the impact?

[oak pond]

ah, not there

just empty

[dark edge]

Show the rest of this

[oak pond]

none of the rest is to do with the hud its other begin play events

[sudden condor]

Important detail :D

[dark edge]

Just show it, I bet it'll show the problem

[sudden condor]

seconded

[dark edge]

or show where you're getting the invalid ref rather if not there

Show
Event -> ??? -> Set HUD
Event -> ??? -> where it shits the bed trying to get HUD

[oak pond]

yeah its specifically on an event that just calls an event on the hud

[dark edge]

I'm betting it's some event that is running everywhere but the HUD is only valid on owning client

[oak pond]

literally just this, but its called from replicated bullet actors. the event still goes through fine though, but just invalid hud

[dark edge]

So that event is called on all machines?

[oak pond]

only to the player that fired the bullet

[sudden condor]

Yeah, try setting that to "run on client"

[oak pond]

I did that, same thing

[sudden condor]

dang well I'm out of ideas

[dark edge]

If you print the value of HUD how many prints do you get

[oak pond]

just one "server: " which is why Im wondering if its because its called from serverside bullets

[dark edge]

https://tenor.com/view/christoph-waltz-thats-a-bingo-bingo-excited-gif-5641363

[dark edge]

what's that

[sudden condor]

What's the key to making gifs work on discord lol

[dark edge]

idk i just click the gif icon here --------------------------------------------------------------------------------------------------------------------------------------------------v

only valid if you're on a tiny monitor

[sudden condor]

(removed because I found it annoying)

eyyy there it is

[sinful tree]

Multiplayer Hit Target example that DJ L3G3ND is trying to do.

[oak pond]

I cant see any real differences with mine

[dark edge]

Since you have the server printing then you obviously aren't doing something right since it should only be running on owning client

[sinful tree]

You're not running the "successful hit" as Run On Client.

[oak pond]

I did

[dark edge]

you can do clientside hits if you want

Bullet:
Hit -> LocalPawn = Instigator? -> yup -> tell it to show some stuff on HUD

[sudden condor]

Keep doing it?

[dark edge]

We really need to see the entire code flow to get an idea of wtf is going on, this is like trying to fix a car looking through a straw.

[sinful tree]

My guess would be that you're calling a "Run On Owning Client" event within the bullet itself rather than on the Character that shot the bullet.

[oak pond]

nope

the bullet gets a reference to the player to call its event, but the bullet itself is like serverside or something because I think it has to be

[sinful tree]

To call what event?

[oak pond]

that one in the player

[sinful tree]

This one?

[oak pond]

yeah

[sinful tree]

You've marked that event as "Run On Client"?

[oak pond]

doesnt make a difference but yeah

[sinful tree]

It does make a difference if what you're trying to do is replicate something from the server to the client.

Without it, the server is likely executing it, in which case the HUD is probably invalid.

[oak pond]

no but Im saying it still fails and does the same thing

I dont even know how

wait I changed something in the bullet itself which may have fixed it

weird, I still cant entirely tell why its like this but

I put it into another run on owning client event on the bullets but I dont know how thats working because who is the owning client in this situation?

[sudden condor]

Each player with their own version of the bullet

I believe

[oak pond]

weird, because that was already happening on every players screen

[open crane]

What’s a good intro tutorial to multiplayer

[dark edge]

Try to make a button that opens a door, without tutorials

[open crane]

...thats not multiplayer related in anyway, whatsoever?

[open crane]

and I asked for a multiplayer tutorial people like. did you not even read the msg?

[plucky prawn]

Stop being rude

[candid mulch]

he meant in multiplayer...

like to replicate it

[open crane]

Ohhhh

Oh

[open crane]

I’m so sorry for misunderstanding

[thin stratus]

I would need to come up with a proper example. But both MoveData for custom data the client wants to tell the server about and ResponseData for Corrections is important imo

I'm not even sure if the repo uses ResponseData to correct the Stamina on sprint or how it was done again. Would need to check. I think all examples use the compressed flags which is the easy version haha

[candid mulch]

its acc harder than it seems

it teaches you server and client stuff idk

[open crane]

Yeah I’ve heard of replication, it’s basically 90% of multiplayer

Bad replication = bad game

[woven basin]

do you find an answer to this?

[woven basin]

did you ever solve this?

[upper lily]

can any one help me figure out this problem?

https://forums.unrealengine.com/t/steam-online-subsystem-session-search-always-empty/1270080

[stable bluff]

hello, im moving my actor on client and i want that change to be on server and on client as well. if i use run on server event the location change only happens of server, and if i just call the func obviously the server doesnt get anything. i looked at multicast but it says i need to run it from the server

is the only way to do it just calling the fucntion 2 times, on server and on client?

[sinful tree]

Mark the actor as replicated. Setting the location on the server will then update on all clients.

Assuming the actor was spawned by the server or placed in the map.

[stable bluff]

?

this?

[sinful tree]

Yep. The location then needs to be set on the server, and it should change for clients as well.

[pearl bear]

How can I replicate FGameplayTagContainer

in C++

[chrome bay]

Mark it replicated. Nothing to it

Note by default it can only replicate 64 explicit tags max.

If you have larger containers, you need to change the default in UGameplayTagsSettings

[pearl bear]

@chrome bay My data asset is on my asset browser, I am just passing it as a argument of the method

[chrome bay]

yeh kk. That should also replicate fine

TL;DR anything you store as an asset in the content browser is resolvable for replication, so any of those should send via network without problems

Going back to your first message in the extremely busy CPP channel, one benefit you might get from the map of tag->anim sequences is tags will probably replicate using fewer bits than a net GUID, so you might get some small benefit doing that.

But you have to opt-in to that behaviour in the gameplay tags project settings (enable fast replication or something).

Should really be on by default, but for whatever reason it's not

But really, my only point was that UObject refs are cheap to send - so if the issue was an optimisation one, DW about it too much

[pearl bear]

@chrome bay it worked, thanks a lot

[fathom aspen]

Wow, this is a TIL!
And I was just looking on a container I was recently working on and it can potentially have up to 63 tags as of now 😆

[whole tree]

how and where to learn Unreal Engine?

[chrome bay]

I know right.. I mean I get why, but man.

Talk about subtle details

[twilit radish]

Jambax saving Wizard without realising it 😄

[twilit radish]

If you want to get started with multiplayer in specific take a look at the pinned messages. There are some great resources in there. If wanting to learn Unreal in general I wouldn't start with multiplayer.

[tight meadow]

if an actor has bunch of replicated variables and RPC's but the actor itself is set to Not replicated, are those variable still going to replicate and RPC are gonna tax performance?

[nocturne quail]

what is bad if someone is using AActor as data for inventory items and C++ UStructs for BP Datatables in multiplayer game?

[stoic lake]

Hey for some reason the hello print string on the multicast only gets fired on the server when the "UpdateChat" gets called on the server, however it does get called on both the client and server when the "UpdateChat" is called from a client

[chrome bay]

Variables won't replicate no. If the actor is statically resolvable, RPC's may work.

[stoic lake]

this is all on the playercontroller btw

[chrome bay]

Multicast doesn't make sense on Player Controller. PC's are only replicated to their owning client. BTW AGameMode::Broadcast() exists for messages, but isn't exposed to BP by default. A tiny bit of C++ would allow you to expose it.

[tight meadow]

so in my case i used a plugin which is multiplayer ready but i dont need the multiplayer part because the game is single player, is it safe to use the plugin as it is or should i remove turn OFF those replication on variables and Disconnect RPC's to save some performance.?

[chrome bay]

Won't make a difference

[tight meadow]

ok, thanks

[whole tree]

thanks you very much

[dark edge]

Just try and don't start with multiplayer

[nocturne quail]

in some only MP frameworks if we start as non-multiplayer , the editor will crash

[thin stratus]

Which is kinda the fault of the person who coded that framework

[chrome bay]

If anything I'd expect the opposite

[nocturne quail]

eg: if our jump logic is only running from the server to clients on multicast and not listening for if locally controlled, pressing jump key will crash the editor

and honestly I like this Idea, the mp game should only work on multiplayer

[chrome bay]

That's not a good idea. What if you're making a game with online + offline play?

I'd fully expect single-player game to crash a lot of attempted in MP, but not the other way around

[nocturne quail]

I will build offline version seperately

[chrome bay]

But you can't if they are the same game

[nocturne quail]

from scratch

[chrome bay]

Just make the MP code not crash, it's far simpler.

If anything MP code should be less likely to crash because it's stricter

[nocturne quail]

combination of single/mp game is a good idea, but it will make the code bigger and stressful

[thin stratus]

@chrome bay I wouldn't argue, That's lost energy :P

[chrome bay]

Yeah, TL;DR, disagree

[half umbra]

hi

i try spawn Niagara from Actor on the map for everyone

when the player collide with the actor then it should spawn niagara but it doesn't, it only happens on the server which is weird because the code is run on the server then multicast but as i printed what happens after multicast is just a print string is on the server

someone can help?

i not spawning actor

i spawning niagara system

in actor

[nocturne quail]

do it on rep-notify

[half umbra]

when i check Reliable

[runic vapor]

hey guys can someone help me make a easy kill count?

[half umbra]

then is ok

but this is only niagara system

i don't want reliable

[runic vapor]

or if you have a video is the same thing

[nocturne quail]

you need a variable on your player state, determine the bullet you spawned and it hit other actor, if the other actor health becomes 0 , kill that actor and ++yourvariable

int32 killcount;

[runic vapor]

oh ok

[nocturne quail]

and you can show that variable data on the screen in a widget if you want

[runic vapor]

okok

[sudden plinth]

Matt aspland has got some good YouTube videos on ue4

[half umbra]

but when overlaping actor, then run this only on server

i want run this for everyone

but multicast don;t run for everyone

so why not replicated this system

[haughty estuary]

Hi all, when I place a replicated actor in the world at edit time (not spawned at runtime), is the server or the client the owner of that actor?

[half umbra]

this is projectile

projectile is REPLICATED

Movement also is replicated

someone can tell my why Print String is only on server

?

if i set multicast to Reliable

then is ok

but it should work for everyone anyway

without Reliable checked

[nocturne quail]

call multicast on server function

[haughty estuary]

It may be easier if I explain what I'm currently trying to do. I have a simple level with 3 replicated actors, the actor has a cube component that when clicked simply toggles a replicated boolean on the actor (rep notify). In the on_rep callback I'm updating a property of the cubes dynamic material (toggling brightness on/off). When I click on one of these cubes from the host I can see the cube brightness toggle on both the host and clients but when I click on one of these cubes on a client I only see the brightness toggle on that client. Do I need to bring in an RPC for this to work?

[half umbra]

doesn't work

all is call on server side

[tardy fossil]

yes

[half umbra]

server call to multicast event

[half umbra]

i seee

[tardy fossil]

all actors are default owned by server so clients can't change any replicated info on them

[half umbra]

i run on server

[nocturne quail]

call server on overlap function and server will call multicast

[tardy fossil]

oh sorry i was responding to @haughty estuary

[haughty estuary]

This is the current result with just a simple replicated boolean and toggling the material param in the on rep callback. I've tried a messing with a few variations of setting up an rpc but couldn't seem to get desired behaviour. Any tips on the flow to make this work from both sides? (both server and clients should be able to toggle the same cubes)

[nocturne quail]

client will need to tell the server to do it, and server will do it for all to replicate

[dark edge]

you need a client -> server rpc to tell server to change the bool

[nocturne quail]

on-rep a state bool will be the best choice

[tardy fossil]

so in your function that gets called when a client clicks on a cube, instead of setting the replicated variable directly, make a new event and set it to Run on server, and have the client call that event function instead of setting the replicated value directly

[dark edge]

also you can't do that in the cube. Gotta do it in a thing the player owns, typically either the playercontroller or pawn

[tardy fossil]

im pretty sure clients can call server RPC's on stuff they dont own

its client RPC's that need that

[clear island]

without "reliable" checked its not expected to always work

so make it reliable if you want to make sure it always works

[dark edge]

nah don't think so

go try it

The RPC has to route through an owned actor. After it's on the server the logic can do anything since it's in the serverside version of the actor the RPC got called through.

PlayerController/Pawn:
Input -> Run on Server Event
Run on Server Event -> change the replicated variable

Cube:
Onrep -> do the thing

[tardy fossil]

oh i guess i missed that since i only call RPC's on things i own lol

[nocturne quail]

• Onrep will save them performance I guess

[normal crypt]

Hi. I have a question about time dilation. How should I replicate it? It seems like the rate of replication is lowered on the clients when I slow the game down. It makes movement very hitchy. While I slow the game down, I accelerate the players so that they move at normal speed. I also manually set the right dilation on the world and all players on all clients.

[haughty estuary]

Sorry, got dragged into a call. I believe @dark edge is right, I did some debugging earlier with different RPC methods and the cube actor would never execute the server rpc (unless it was the host). The RPC has to route through an owned actor. After it's on the server the logic can do anything since it's in the serverside version of the actor the RPC got called through. this feels like it's going to be the solution I just need to figure out where/how to call that server rpc (there's no pawn available so I'll test it out on the controller first and see if I get anywhere)

[half umbra]

Actor should be destroyed always from Server?

[dark parcel]

I think you can call server RPC on the cube actor from the client if the client is the owning actor

[half umbra]

if Actor was be destroyd on server then client still have copy?

[tardy fossil]

probably not the best solution, but you could stick the server event into the Player Controller class and have it take the cubes Actor object as a second input

[haughty estuary]

@dark parcel yes, that would mean the hosting client can click the cube and it would run the rpc (on his machine since he's running the server), however from the client that isn't hosting they don't own the actor so the server rpc will not be executed. I'm just trying to change it a little now so that the click event in the cube gets an object owned by the current client (controller) and calling a server rpc from there passing the clicked cube actor along. I'll also try doing the same from game state, I think that feels like a better place for this rather than controller but could be wrong 🤔

[dark parcel]

You probably don't want to do stuff from the client outside the pawn and controller. It will open ways to cheat

[dark parcel]

Yeah I could get hover event on cube actor to work on cleint side but I need to set the ownership first

[half umbra]

ok, is it normal that sometimes niagara shows up and sometimes not? always shows up on the server

[dark parcel]

you probably didn't spawn copies for the client

sfx should be local to each client

[dark edge]

just show your code

from whatever event triggers the thing all the way to the bit where you spawn the niagara system

[shrewd ginkgo]

I make a name system for lobby but I want to see players name in game if I bring the crosshair on other players name how can I do it

[half umbra]

this is Actor

if hit player then spawn niagara

for everyone

if server

do important logic

[dark edge]

In what case do you want it to spawn the system and on which screens?

What mechanic are you actually trying to implement here.

[half umbra]

I want it to spawn in everyone

[dark edge]

You want the particle to spawn attached to which pawns on which machines?

[half umbra]

attached to Players

Instigator is a player who initiated the hit

[dark edge]

You want to see the XP on the instigator's pawn only or on everyone's pawn?

[half umbra]

or instigator pawn

but

everyone see this

[dark edge]

Make a multicast event GainedXP in your pawn class

have THAT show the particles

When the hit happens:
Hit -> Authority? -> yes -> call Instigator.GainedXP -> do other server-only stuff

[half umbra]

I thought about it too, but sometimes what I showed in the picture shouldn't work?

[dark edge]

What you showed in the picture is all sorts of fucky

[half umbra]

xd

ok, and multicast on actors that the client doesn't own then doesn't make sense

yes?

[dark edge]

Here's what your code is literally doing:
Hit happened -> check if you hit the instigator (?????) -> cast the hit actor to Character (you already know it is because it's also the instigator) -> spawn a particle system -> authority switch for some reason -> run on server RPC for some reason (you already know you're on the server version from the authority switch) -> unalive self

[dark edge]

The SERVER version of that actor is making the call

only server can call multicast

[dark edge]

You want to do it this way so then anything that grants XP can just call this

In fact you'll want 2 events:
GrantXP (this is just a normal event)
OnXPGain(multicast)

Anything:
??????????? -> Has Authority? -> call GrantXP on some character(passing in the amount of XP granted)

Character:
GrantXP -> do xp logic -> call OnXPGain(multicast)
OnXPGain -> do the visuals and sound etc

[haughty estuary]

Thanks for the feedback everyone, it works as expected though I'm going to keep experimenting some more, not entirely sure it's the best/correct way yet but it does what I set out to achieve so that's a win 🤘

The one piece that doesn't feel right is getting access to the player controller from the cube actor, it uses gameplay statics get player controller which requires an index but after starting to read this document that might be a bad smell later down the road. https://wizardcell.com/unreal/multiplayer-tips-and-tricks/#2-beware-of-getplayerxxx0-static-functions

[dark edge]

why is the cube talking to the PC?

PC should talk to cube

[haughty estuary]

This was the final result. The part I was struggling with was getting the cube actor to call the server rpc but the hint from @dark edge The RPC has to route through an owned actor. was key to getting this first multiplayer test working!

[dark edge]

So that's just to use the ActorOnClicked event

not the worst but also not great, you could also do it from the perspective of the PC

PC:
Input -> figure out stuff (which cube if any, etc) -> call run on server event
run on server event -> ??? -> end up with something changing the bool

Cube:
Onrep_bool -> change stuff

If you have a bunch of stuff, not just these cubes, I'd probably start it from the PC

[haughty estuary]

I'll have a look a changing it up a bit, I went down this route just because I could quickly handle the clicks on the cube without figuring out how to detect clicks of the light cubes directly from the PC yet but if that's a better approach I will certainly look into it

[dark edge]

It's better if there's a lot more clickable stuff

[haughty estuary]

from a perf/mem point of view? Having one click handler setup on the PC rather than a click handler per light cube? or for other reasons?

[dark edge]

Yeah the click handler

instead of object telling pc it got clicked
pc making that call

then the objects can just be dumb actors with a few onreps and thats it

Now i wonder if you can manually call that onclicked event

that might be something worth doing, but it all depends

[hollow flicker]

Is there any way of hosting a multiplayer game as a listen server, when I cannot port forward on my own wifi? Ive heard about doing a NAT punchthrough but couldnt find any resources on it.

[haughty estuary]

Ooo, just discovered the set of functions for detecting what was clicked GetHitResultsUnderCursor[by|for]XXXX this could be handy from the PC within a mouse click handler!

[dark edge]

If you're serious about it the best bet is to integrate Steam or EOS

why can't you port forward?

[haughty estuary]

I feel if I'm moving the click handling into the PC then I'll likely remove the click event handler from the light cube completely, kinda makes sense now I'm talking about it with you, maybe later an AI controller pawn might touch a cube to light it up so it makes sense for the ai controller/pawn to just call toggle power or something on the light cube rather than imitate a click 🙂

[hollow flicker]

Well, I really just wanna try out my game at this point with a few friends and dont wanna break much of my networking stuff again. Would integrating that be a lot of work or need like a total rework? Or is there an easier way with just my direct connection setup?

[hollow flicker]

I dont have access to the wifi

[dark edge]

Your options are pretty much forward the port or use Steam or EOS or your own code

You could also spin up a dedicated server somewhere but that's about as complicated

[dark edge]

your buddy can host if he can port forward

[half umbra]

can you explain me why multicast doesn't do print string for all?

[dark edge]

I would multicast in the character, not in whatever this is

[hollow flicker]

Would that require a lot of work? Any resources on those two services?

[dark edge]

is the actor replicated?

[half umbra]

yes

actor replicated

[dark edge]

https://github.com/mordentral/AdvancedSessionsPlugin
is probably the easiest

[half umbra]

will you explain it to me? 😅

[clear island]

are you still using "unreliable"?

[half umbra]

what I showed in the image is in Actor graph

[half umbra]

yes

[clear island]

use reliable then

[half umbra]

nope

[dark edge]

#multiplayer message

[half umbra]

reliable is not for visual effects

[dark edge]

motherfucker you already thumbsupped my explanation lmao

[clear island]

this may shock you but, "unreliable" is in fact unreliable

so you either use reliable RPC or replicated variables

choose

[dark edge]

yes but it'll usually go through unless the pipe is clogged, you don't want to prioritize cosmetics over actual gameplay-important stuff

not a big deal if a particle doesn't spawn or is late

[clear island]

yep

[dark edge]

I can't really think of a use case for a reliable multicast but I'm sure there might be one

[clear island]

for fast paced combat games it is preferable to replicated variables imo

(if its stateless stuff ofc)

using too many replicated variables also has its issues

[haughty estuary]

@dark edge Does this make more sense? There's now no click event handling on the light cube, all it knows how to do is toggle a replicated boolean which in turn updates the material when changed. The PC now handles clicks and if clicking on a light cube will call a server rpc on the PC which simply calls the toggle power event on the clicked light cube. I understand I could get interfaces involved here too so that PC isn't coupled to light cube. It certainly feels to be a better approach (rather than light cube knowing about clicks)

[dark edge]

You might want an interface eventually but yeah that's good

[hollow flicker]

Im only finding resources regarding that for steam. How would it work for mobile?

[haughty estuary]

Thank you so much for your guidance, was banging my head on this for hours last night wondering why the server rpc wouldn't run 🥲 you've helped me out massively here!

[dark edge]

now you're wanting to throw mobile into the mix?

You really have bit off a big old chunk

[thin stratus]

There isn't really any Multiplayer specific things with EnhancedInput

Maybe only that you should add Context etc. locally

But that's not IE specific :P

[dark parcel]

https://forums.unrealengine.com/t/listen-server-clients-animations-are-jittery-laggy/689493

Is there a fix to this problem? Like we can replicate it in any template

[thin stratus]

There was once, but I don't know how to do that anymore with recent CMC changes

[dark parcel]

When playing as listen server, other player animation looked raw. But Clients see each other fine

[thin stratus]

You would need to override PossessedBy in C++ and skip the ACharacter call

And then make sure the CMC isn't ticking the pose

But that doesn't seem to be that easy cause the CMC part got more complex

[dark parcel]

Hmmm

[thin stratus]

At least from the looks of it

[dark parcel]

Maybe dedicated server is the only solution

[thin stratus]

Dedicated vs Listen is not a matter of jittery animations ¯_(ツ)_/¯

[dark parcel]

or dive deep into CMC for the sake of listen server

i will see what where fate bring me

[dark parcel]

Client see each other fine

no jitter what so ever

[oak pond]

has anyone heard of players camera rotation getting reset when another player joins? I cant tell if its something Ive somehow caused or something else

[dark parcel]

only Server see other animation "raw"

So if everyone play as client, it's a happy world

[thin stratus]

Well that's mainly cause you put the code into the wrong places

You could do BeginPlay if you lock it to IsLocalPlayerController

Or you put it into SetupInputComponet?

Lots of places. PossessedBy is Server only

So that fails the local player part, yus

[thin stratus]

Most likely your fault :D

[oak pond]

[thin stratus]

Yeah it's because (Listen)Server "ticks" the Anims via ServerMove calls

[oak pond]

I dont even know what Ive done this time, Ill have to look

[dark parcel]

Ahh ok and the possible fix is
Skip the ACharacter call and
making sure CMC doesn't tick pose?

[thin stratus]

Yop

[dark parcel]

thanks, will look into it

[thin stratus]

ACharacter possessedBy sets that bool that stop the server from ticking

iirc

Well ticking the pose

But I don't know about the tick pose anymore

That was one place before

[dark parcel]

@thin stratus bOnlyAllowAutonomousTickPose=false Do you mean this tho?

[thin stratus]

now it's different

Yeah

[dark parcel]

Because that doesn't really fix the problem. The animation will run as twice as fast

it's like depending on tick

[thin stratus]

Yeah cause you have the CMC Tick the pose :P

[dark parcel]

OHhhh

ok so I am probably missing that step

gonna SS this so I can remember

Thanks

am i gonna get into trouble for disabling pose tick on CMC?

[thin stratus]

Probably not

I'm pretty sure we shipped The Ascent with that

I mean

Originally it was one line that called TickPose

That was easy to fix

Now it's called in multiple places

[dark parcel]

🫠

[thin stratus]

And has its own weird function

I tried disabling that yesterday for something else and that was breaking stuff

Specifically for RootMotion, but still shite

[dark parcel]

Someone was saying to toggle it depending if root motion is playing or not

but that reddit post have since gone

[thin stratus]

Never got anything good from Reddit haha

Seems to be only good for placing pixels lately

But yeah, you'll have to play a round with it

[dark parcel]

🪦

[thin stratus]

And probably see what the different TickPose calls are for

Makes no sense to remove somethign wtihout understanding it

[oak pond]

oh man I cant stand how things are always different for the host of a server man

how do you even generally fix that

[simple bough]

hi can anyone guide me how to use multi user edit in ue 5?

[thin stratus]

Buy your clients good PCs

[oak pond]

no like the way events work differently based on how theyre set up

[thin stratus]

Can only really link the docs

[simple bough]

no i mean , yes we can share the data by through doc/github but can we work on same project in ue 5 and also edit works in same project in ue 5

[thin stratus]

With docs I meant documentation

Documentation of Multi-User Editing

Not that you share the documents

:P

[simple bough]

ahh yes

[thin stratus]

https://docs.unrealengine.com/5.2/en-US/multi-user-editing-in-unreal-engine/

There should be a getting started guide

[simple bough]

thank you 👍

[oak pond]

even non replicated events too? how does that even work

[thin stratus]

Not sure I follow

[oak pond]

you know when you start a listen server and the other guy joins, events work different for host and client

[hollow eagle]

As a general thing? No they do not.

[thin stratus]

I mean there are some rules, but despite that, things work quite similar

[oak pond]

then how have I even accidentally caused that

[thin stratus]

No clue. You probably did something somewhere that is wrong

As stupid as it sounds, no clue how we would know what you did wrong

You will have to start debugging

[oak pond]

yeah Ive definitely done plenty wrong but Im kinda trying to ask about the general setup of this kinda thing because I thought that just happens

[thin stratus]

Camera Rotation, if you didn't do anything else, is probably following ControlRotation

[oak pond]

I fixed that, I dont mean that now

its several things, one being only the host can take damage (from enemies and other players) so not sure what needs changing in the bullet projectiles because enemies take damage in the same way and that replicates

[thin stratus]

You usually deal damage on the Server side and have a Replicated (or even RepNotify) HealthVariable

+- some local prediction if needed, but in it's most naive form that's it

Projectile Overlaps Target, ensure SwitchHasAuthority, call Damage interface, or whatever you use, on the Overlapped Actor

Isn't really rocket science

[oak pond]

ah, maybe Im just overthinking it, the actual damage event specific to the player wasnt multicast, must have been confused because of how Ive been working on the enemies recently which are server based

[brisk fulcrum]

How can i change level to all player

[gleaming kite]

Is there a delegate I can bind to for when an actor becomes net relevant (Either through first join or entering its net relevancy range)?

[dark edge]

Begin play

[gleaming kite]

Or actually better yet, can I make a rep notify only replicate/fire when its parent actor becomes net relevant?

[gleaming kite]

oh sweet, i didnt know it gets fired again when it becomes net relevant, that makes sense, thanks!

[dark edge]

Repnotify should do that already too, test that

I'm not 100% on it but I think the repnotifies should fire

[gleaming kite]

well i want it to only fire when becoming relevant and not after

ill just use begin play and make the var only replicate

[sinful tree]

If it's blueprint only, I think the RepNotifies will only fire if the value is different than what the default is, so depending, it may or may not fire when returning to relevancy.
Begin Play is the way to go to know if an actor is relevant.

[brisk fulcrum]

help

[valid bough]

Can someone please point me to the right direction on how to connect 2 clients together using the steam subsystem? I set up the SDK and what not, which the documentation for that is severely out of date.

Supposedly Steam OnlineSubsystem is broken in 5.0+ gotta use advancedSessionsPlugin?

[mystic estuary]

Does anyone know whether it's possible to know what was the previous map the game has taken place on?

[dark edge]

save that in gameinstance

[mystic estuary]

Sadge, I thought that there is some other way. All right then 😄

[sinful tree]

Advanced Session Plugin works. Have one client create a session and move to the desired level. Have the other search for sessions and when it finds one, join it.

As far as using steam subsystem, I'd recommend you try in #online-subsystems

[haughty estuary]

Just reading through this document https://docs.unrealengine.com/4.26/en-US/InteractiveExperiences/Networking/Blueprints/ trying to make more sense of what sort of logic belongs on game mode and game state. This document had an interesting description for the game mode which I've not come across before (usually game mode is described simply as the rules/flow for the game) but in this doc it mentions a game rule about rocket launchers only and goes on to mention when randomly spawning weapons around the map on the server that this rule should be respected, would that mean in this scenario the game mode is responsible for spawning the weapons OR just that some actor owned by the server will ask the game mode about this rule to determine which weapon to spawn? Most game mode classes I've seen are quite slim, used for nothing more than just assigning default framework classes mostly.

[sinful tree]

By default the game mode is responsible mostly for handling joining and spawning of players and defining the other gameplay classes being used. That's about it.
Any further rules you want to apply to a game can be handled at the actor level with some variables defined within the game mode if needed assuming the relevant actors are being spawned by the server of course.

[valid bough]

Got it thank you!

[soft cape]

I am currently trying to get a host to pull in my party into a "Lobby" map. The host creates a session, then OpenLevel() and then calls a ServerTravel(). This works sometimes, but occassionally the client that travels get connection timed out. I notice the logs on the client-side don't really match up with the hosts'.

(Host Opening Lobby)

[2023.08.24-20.36.41:013][ 37]LogEOS: Verbose: CreateSession: Successfully created session 'Default'
[2023.08.24-20.36.41:057][ 37]LogNet: Browse: /Game/Maps/Lobby?listen
[2023.08.24-20.36.41:057][ 37]LogLoad: LoadMap: /Game/Maps/Lobby?listen

(Client Joining (Timedout))

[2023.08.24-20.36.41:377][454]LogEOS: Verbose: JoinSession: Successfully joined session 'Default'
[2023.08.24-20.36.41:378][454]LogNet: Browse: <ip-address>/Game/Maps/Launcher
[2023.08.24-20.37.01:409][757]LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = ConnectionTimeout, ErrorString = UNetConnection::Tick: Connection TIMED OUT. Closing connection.. 

I assume things aren't working because the map is not updated on the client side

[haughty estuary]

What about when it comes to processing rules such as win conditions. If we take team deathmatch as an example, that game mode may have a configurable value for team kills required to win, every time a player is killed the server would update the game state to +1 on a team scores, then is it the responsibility of the game state to check team score >= kills required or does the game state ask the game mode to do that check so that it can transition to the next state if a team has won? 🤔

[sinful tree]

The game state would probably read a value that is set in the game mode to determine if the max kills has been reached.

That value could also just be stored in the gamestate directly by having the game mode setting in there in the first place when it knows.